bald spot / generally rough looking backside on Cochin

I had two lovely golden comets and added a Cochin who needed rehoming to my little flock. Everyone seems to have adjusted well, and they are all flocking together and doing well. The Cochin is a bit bossy, but it all worked out.

However, the Cochin has two bald patches under her wings and her whole backside is looking a little rough - broken/missing feather, just kinda ratty. She is eating and laying (2/week) and behaving just fine, so I was thinking molt and/or rehoming stress, but it has been a few weeks now and she still looking a little rough back there.

Any ideas? Maybe Mites? She has access to layer feed, oyster shell, grit and water, free ranges for 1 to 2 hours daily, has access to a grass in her coop and gets a good mix of table scraps.

Or am I over-thinking this, and it is just molting and/or rehoming stress, and those things take a while?

Look her over for signs of lice, mites, or their eggs. Overcrowding, a diet too low in protein, or boredom can cause feather picking. Make sure they are receiving a 16 or 20% protein feed, either layer or an all flock feed. Let them out to free range daily. If there is feather loss previously, the hen may not re-grow those feathers until her next full molt. Chickens molt first around 16-18 months, and then once a year thereafter. Permethrin dust or spray is very good to treat mites or lice. Here is what to look for:

Permethrin spray or the garden dust are pretty easily found at feed stores and TSC. For lice use them once every 10 days to get the eggs as they hatch, until they are gone. Empty the bedding from the coop and spray the coop nests, and roosts, and replace bedding. They can be a challenge to get rid of. Lice eggs can be removed with coconut oil according to some people on BYC.